Heidi McDonald and her family follow a strict routine when they come in after spending time outdoors.

To someone who has never suffered from Lyme disease, the family of four’s precautions might seem paranoid. But McDonald said she isn’t taking any chances with the tiny deer ticks that have made her very ill.

“We leave all of our clothes in the garage, literally strip down to our underwear, then go jump in the shower and we use a brush in the shower,” McDonald said. “Then we check each other.”

Spotting ticks requires time and patience, but so does waiting six months for a diagnosis once Lyme disease takes hold. McDonald, 54, of Buxton, never suspected the bacterial infection when she started having pain in June 2011. The discomfort began in her lower back, but grew worse, into a sensation she described as a combination of a sunburn and being struck by a baseball bat.

Her doctor X-rayed her back, found nothing, and suggested pain medication, which McDonald refused because she worried about the side effects.

That fall, she said her right foot “blew up, it was round, red, and hot to the touch.” Later, she tried a cortisone injection in her spine for the back pain. After misdiagnoses and ineffective chiropractic and acupuncture treatments, McDonald finally went to a doctor recommended by her family.

After testing, she officially was diagnosed in January 2012 with not only Lyme but also babesia, another infection spread through the bite of the eight-legged deer tick. She also has bartonella, another infection that’s carried by insects. She was referred to a Lyme specialist and recently stopped taking rounds of antibiotics, though she still suffers from symptoms, including confusion.

“We’ve seen increases every year for the last four or five years,” said Dr. Stephen Sears, state epidemiologist. “There’s no reason to suspect that we won’t potentially see more cases because it appears that Lyme’s moving into parts of the state where it was not as common before.”

Lyme first appeared in the southern part of Maine, and has consistently spread north and Down East. Lyme disease in humans now shows up in every county in the state thanks to hungry deer ticks that feed mostly during the summer months.

It’s estimated than an average of 50 percent of Maine deer ticks carry Lyme disease, though the infection rate can be much higher or lower depending on the region.

“People still don’t think about wearing protective clothing and using repellants when they’re going out into potential tick-infested areas,” Sears said. “And I don’t think that they’re doing as careful a tick check as they might. We can’t stress that enough, because the ticks usually wander around for a while before they embed. So if you do a good tick check — and really look around, under the hairline, in the armpits and the groin — you can often find them and get rid of them before they attach.”

Sears and McDonald both stressed the importance of early diagnosis for Lyme disease. While a characteristic “bull’s-eye rash” is the most common symptom of the infection, the rash wasn’t found in half of the Lyme cases identified last year in Maine, according to a Maine Center for Disease Control and Prevention report.

McDonald said she never saw the bull’s-eye rash on her body.

Detecting and treating the disease early can limit the symptoms to fever, chills and body aches, before the infection leads to later-stage problems including joint pain and neurological issues.

“The scariest part is not having a diagnosis,” McDonald said. “The second scariest part is when it affects your brain.”

For McDonald, finding a doctor well-versed in Lyme who took her symptoms seriously has made all the difference, she said.

“You sound like you’re crazy,” she said. “If the people around you didn’t love you and believe you and know you so well, you’d really feel like you’re losing it.”

A bill now under debate in the Maine Legislature, LD 597, would direct the Maine CDC to inform patients about different alternatives for the treatment of Lyme disease.

McDonald, who advocates for Lyme disease awareness, pointed out that testing for Lyme disease isn’t always conclusive. The most common test, called the ELISA test, can provide false positive results or fail to detect Lyme in its early stages. Many doctors won’t perform a second test, the Western blot test, without a positive ELISA result.

McDonald is thankful that her doctor was willing to administer the Western blot test after her ELISA test came back negative, finally leading to her diagnosis after months of uncertainty, she said.

For information about Lyme disease, visit the Maine CDC website at maine.gov/dhhs/mecdc. McDonald also recommended the International Lyme and Associated Diseases Society, www.ilads.org, an organization that has not been endorsed by the federal CDC.